Extended Hypervalent 5c–6e Interactions: Linear Alignment of Five C─Z- - -O- - -Z─C (Z = S, Se) Atoms in Anthraquinone and Anthracene Systems

Abstract

Structures of 1,8-(ArZ)2C14H6O2 and 9-(MeO)-1,8-(ArZ)2C14H7 (Z = S, Se) are determined by X-ray crystallographic analysis. Five C─Z- - -O- - -Z─C atoms of the compounds align linearly, which are analyzed by the extended hypervalent 5c–6e model, based on QC calculations. CT of the 5c–6e occurs as the σ*(C─Z) ← n p (O)→ σ*(Z─C) direction.